The invention relates to outboard motors, and more particularly to outboard motors with four-stroke engines. The invention also relates to lubrication systems for four-stroke engines.
It is known to lubricate a four-stroke engine of an outboard motor with oil from an oil sump or reservoir located in the driveshaft housing. It is also known to have an oil pump driven by the lower end of the camshaft, and to have the pump provide oil to the crankshaft bearings and the camshaft bearings via oil passageways in the cylinder header and cylinder block. It is also known to lubricate connecting rod journals with oil passages extending through the crankshaft from the crankshaft bearings to the connecting rod journals. See, for example, U.S. Pat. No. 4,452,194.